Abstract： Objective To investigate the expression of p53,bcl-2,and bax,apoptosis regulating genes,in adenoid cystic carcinoma of larcrimal gland and the roles thereof in elinical prognosis.Methods 56 patients of adenoid cystic carcinoma of larerimal gland were divided into two groups according to the prognosis:poor prognosis group with recurrence or metastasis within 5 years(n=32)and better prognosis group(n=24)surviving tumor free within 5 years.The protein expression levels of p53,tumor suppressor gene,bax,apoptosis promoting gene,and bel-2,anti-apoptosis gene,were analyzed by strepavidin peroxidase method.8 cases of normal lacrimal gland tissues were used as controls.Results(1)The overall positive rate of p53 of the patients with adenoid cystic carcinoma of larcrimal gland was 73.2%.significantly higher than that of the normal controls(0,P<0.05).The p53 positive rate of better prognosis group waft 62.5%,significantly higher than that of the poor prognosis group(81.3%,P<0.05).The protein expression of p53 in adenoid cystic carcinoma of larerimal gland was negatively correlated with clinical prognosis.(2)The overall expression rate of bcl-2 of the patients with adenoid cystic carcinoma of larcrimal gland was 69.6%,significantly lower than that ofthe control group(P<0.05).The expression bel-2 protein was correlated with better clinical prognosis.(3)The bax positive rate of the patients with adenoid cystic carcinoma of larcrimal gland group was 60.7%.not significantly lower than the control group.The bax positive rate of the better prognosis group was 91.7%.significantly higher than that of the poor prognosis group(65.6%,P<0.05).Conclusion Some apoptosis regulating genes,such as mutation-type(mt)p53 play an important role in the gene ration and development of adenoid cystic carcinoma of larcrimal gland.p53,bax,and bel-2 proteins may act as valuable signals for clinical prognosis.The patients with over expression of bcl-2 and bax and low expression of p53 may have better prognosis than the contrary ones.